Research Project Examines Galaxy’s Magnetic Fields
VMI’s observatory at McKethan Park is enabling research that will contribute to the understanding of our galaxy’s magnetic fields.
Cadet Philip Wulfken ’13, a physics major with minors in astronomy and mathematics, is working with Lt. Col Greg Topasna, associate professor of physics, on a capstone project examining galactic magnetic fields by studying the polarization of starlight.
“There are tiny particles that get aligned with the magnetic field of the galaxy and, depending on their alignment, light that comes through will be slightly polarized,” said Wulfken. “So by looking at that you can detect the magnetic fields.”
Wulfken is collecting data from five stars and meticulously analyzing that data to calculate the starlight’s polarization and how that translates to the alignment of interstellar dust.
“What we want to do is to look at the interstellar magnetic field on a small scale and see what the alignment looks like,” said Topasna. “We’re mapping the field very precisely.”
The stars were chosen, in part, because of their distance from earth, since stars that are farther away come through a greater quantity of interstellar dust.
“Most stars emit unpolarized light. We’re looking at stars that are farther away so that they have time to travel through this interstellar medium, come into contact with interstellar dust and become polarized,” said Wulfken.
The research has given Wulfken insight into the painstaking nature of astronomy.
“When we were taking data over the summer we were there from 7 p.m. until 4 a.m. Most of that time was just waiting for the detector to take data,” said Wulfken. “When you’re taking a few hundred images of several different stars, it takes a while.”
Without VMI’s own observatory this kind of research would have been next to impossible, since it would have been difficult to borrow enough time on a large research telescope to collect the necessary data.
“It’s nice to have our own telescope. It might not be as big as some of the telescopes that are out there, but we get permanent access to it,” said Wulfken. “It’s nice to be able to go there at your convenience and collect your data.”
The fact that VMI researchers have access to their own observatory also allows them to monitor the skies over time.
“To get the best data, we have to monitor the polarization over a long period of time,” said Topasna. “We can do that since we have our own telescope to use whenever we need it.”
The telescope, a 20-inch reflector, is being used in conjunction with a polarimeter that Gerald Popko ’10 worked to design and build during his time at VMI.
The polarimeter is a device that detects the degree of polarization of starlight by means of lenses, filters, a Wollaston prism, and a CCD camera.
“When I was a rat, my company’s commander was a physics major and he was working on this project, so there’s definitely a lot of continuation there,” said Wulfken.
Wulfken shared his research during the Sigma Pi Sigma quadrennial physics conference, which took place Nov. 8-10 in Orlando, Fla.
By John Robertson IV